In tropical Asia, influenza activity continued to decline in most countries. In northern Africa and western Asia, influenza activity remained low in most countries, with influenza B the predominant virus detected.

In the southern hemisphere, influenza activity is still low, although in some countries influenza-like illness (ILI) activity is slowly increasing. Influenza detections were still low.

Based on FluNet reporting (as of 15 May 2014, 09:00 UTC), during weeks 17 to 18 (20 April 2014 to 3 May 2014), National Influenza Centres (NICs) and other national influenza laboratories from 81 countries, areas or territories reported data. The WHO GISRS laboratories tested more than 40 300 specimens. 3739 were positive for influenza viruses, of which 1696 (45.4%) were typed as influenza A and 2043 (54.6%) as influenza B. Of the sub-typed influenza A viruses, 278 (31.2%) were influenza A(H1N1)pdm09 and 613 (68.8%) were influenza A(H3N2). Of the characterized B viruses, 49 (89.1%) belong to the B-Yamagata lineage and 6 (10.9%) to the B-Victoria lineage.

Source of data

The Global Influenza Programme monitors influenza activity worldwide and publishes an update every two weeks.
The updates are based on available epidemiological and virological data sources, including FluNet (reported by the WHO Global Influenza Surveillance and Response System) and influenza reports from WHO Regional Offices and Member States. Completeness can vary among updates due to availability and quality of data available at the time when the update is developed.